My drawing shows electrodes on a single wrist and it is correct. Your drawing shows different thing, it’s about wrist-to-wrist connection.
Now, going back to dr. Beck, who started all this: he used to use wrist-to-wrist technique, but soon found out that electrodes on a single wrist are equally effective. Yet, he never changed his mind about the current needed to be applied! This is a quotation from his paper „Take back your power!”, page 5:
„Recent (Dec. 1995) research suggests that placing both electrodes over different arteries on the same wrist works very well (see pg. 7), avoids any current through heart, and is much more convenient and just as effective...”
Wrist-to-wrist connection still features electrodes placed on the surface of the skin, still the current goes thru the skin, thru the tissues and thru the walls of the vessels before it reaches the blood.
Look, your drawing misses one thing: it is a resistor, which should be connected pararelly. This resistor represents the human body as a whole. It is total resistance of all human skin, tissues, vessels, bones etc. which happened to be between both electrodes. Try to calculate its total surface – the current will flow literally EVERYWHERE it can – that is how electricity works.
Bob Beck did his clinical research and measured all of this in real. Have you? Moreover, he had nothing to sell!